Coal distributing apparatus for stokers



June 20, 1944. w. T. HANNA COAL DISTRIBUTING APPARATUS FOR STOKERS 4 sheets sneet 1 Filed Sept. 26, 1940 TOR INVEN Thompson Hanna Julie 20, 1944. I w HANNA 235L960 COAL DISTRIBUTING APPARATUS FOR STOKERS Filed Sept. 26, 1940 4 Sheets-Sheet 2 INVENTOR I Wzllz'am Thompson lialrman June 20, 1944. w T HANNA GOAL DISTRIBUTJNG APPARATUS FOR STOKERS 4 Sheets-"Sheet 3 Filed 'Sep't. 26', 1940 IINVENTOR Thompson Hanna mn g INVENTOR if William Thompson Hanna Patented June 20, 1944 TEN-T OFFICE COAL DISTRIBUTING APPARATUS FOR STOK-ERS William Thompson Hanna, Cincinnati, Ohio Application September 26, 1940, Serial No. 358,395

Claims.

The present invention pertains to stokers for coal-firing fireboxes of boats and locomotives andmore particularly to improved apparatus for distributing coal by fluid blasts. directed over the firebox.

In apparatus of this type blasts of steam or other elastic fiuid are directed over the firebox and coal moving into the blasts is carried to the difierent parts of the firebox. Cooperating with a so-called blast chamber, from which the blasts or jets issue, there is adistributor plate below and forward of the jets which coacts with them to direct the coal along certain paths. Such distributor plates are usually at least partly within the firebox proper and are subjected to the intense heat of the fire and so normally have a relatively short. life and must be readily replaceable. Also, with such apparatus the problem exists of getting desired distribution of coal to the sides and rear back corners of the firebox adjacent the distributing apparatus. This problem is more acute where the firebox is relatively wide and where the firing opening in which the coal distributing apparatus is located is only a relatively short distance above the firebed level.

It is an object of the present invention to provide improved distributing apparatus and to provide improved distributor plate mechanism which is readily replaceable in part or in whole and which is adapted to feed coal to the rear corners of fireboxes of any type so that uniform distribution of the coal in proper proportion to all sections of the firebed may be obtained, with particular attention to the sides and back corners.

Further, since such distributing apparatus is usually located within the firing opening of the firebox it is desirable that the distributing apparatus be constructed for efficient firing without requiring changes in the positioning or size of the firing opening and without obstructing the opening. And it is another object of the present invention to provide improved apparatus which is adapted to fire the sides and the rearward corners without requiring changes in the firing opening even though the firing opening be located relatively a short distance above the firebed and to accomplish this without obstructing the firing opening either for occasional handfiring or for the entry of boiler repair workmen.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawings, in which are shown two embodiments of this invention,

Figure 1 is an axial section through a portion 1 ofia conveyor system delivering coalfrom a ten,-

utmost) der to distributing apparatus embodying the'invention and'located in .a firing, openingin the back wall of .a locomotive firebox;

Figure 2 is an enlarged top plan View of the distributing apparatus shown inFigure 1;

Figure 3 is.a front elevation of the distributing apparatus of Figure 2 lookingat the apparatus from within. the firebox;

.Figure l is a vertical section taken on line 4-4 of. Figure 2;

Figure 5 is a top plan of another embodiment of .my, invention showing certain elevated distributor arms removable from the main distributor plate body;

Figure 6 is a front elevation of the structure shown in Figure 5;

Figure 7 is a side elevation of the structure of Figure 5;

Figure 8 is a vertical section taken on line 0-8 of Figure 5 and showing a blast chamber Figure 10 is a top plan of the distributing apparatus of-Figure vSshown located in a .firing opening and diagrammatically showing the firebed areas reached by different sections of the distributing apparatus.

Referring to the left side of Figure 1 thereis shown in cross-section and numbered I0 a boiler backhead of a locomotive firebox. This backhead has a firing opening I l and'grates H2 at the bottom of the firebox. .Encompassing the firing opening is a coal delivery housing generally indicated at 13 provided with a hand-firing opening l4 aligned with the firing opening ii and adapted to be covered by theusual fire doors, not shown. The-housing l'3 .is secured to the back- Entering the housing from below is. a riser conduit ll through which coal is delivered into the housing l3 by means of conveyor screws I8-operating in'conduit l9 extendingfrombe- .neath thecoal bin onthe tender to the riser conduit i'l. As the screws rotate coal iscontinuously removed from beneath the coal bin on the tender and transferred forwardly past a usual icrusher tothe housing 13 where it maybe conditioned and its fiow regulated by a pair of oppositelydisposed rotatingtapered screws 20 and cause to flow over a delivery ledge 21 as described in myPatent No. 2,044,001, issued June '16, 1936.

The coal thus suppliedtothe-housing l3 and flowing over the ledge 2| is distributed over the firebox by distributing apparatus indicated generally' at 22 and comprising a blast chamber generally indicated at 23 and a distributor plate generally indicated at 24. The distributing apparatus distributes the coal by means of steam blasts issuing from the blast chamber and reflected from the distributor plate.

The blast chamber may be of the type described in my Patent No. 2,192,190, issued March 5, 1940, and in the present embodiment comprises, as shown in Figures 2, 3 and 4, a body portion having a top ledge 2|a in front of and in the plane of said ledge 2| of the housing l3. The body portion is provided with a high pressure chamber 25 running lengthwise of the body portion and a low pressure chamber 26 (Figure 8) also extending lengthwise of the body portion. Extending forwardly from the high pressure chamber and through fingers 21 forming a grill work are apertures through which the steam flows from the high pressure chamber in the form of high pressure jets. The fingers have a fan arrangement and the tops of the fingers slope downwardly and forwardly so that coal coming from the ledge 2| falls. down over the fingers and is screened, the small particles falling down between the fingers and the larger particles riding over the fingers into the path of the high pressure jets which carry such particles to different portions of the firebox. The fine particles are picked up by a sheet jet issuing through an arcuate elongated slot 28 extending across the front of the body portion and connecting with the low pressure chamber 26. The spreading low pressure sheet jet issuing from the armate slot 28 carries the finer particles over the different portions of the firebed.

The extreme end fingers 21a are shorter than the others so that coal particles riding down between the fingers 21a. and the fingers immediately adjacent tend to fall sidewise into jets issuing from the fingers 21a. This aids in obtaining desired coal feed to the sides of the firebox.

The blast chamber is secured in place in the lower portion of the firing opening against spaced webs 3| extending forwardly from the underside of the housing l3. This is accomplished by securing flanges 29 (extending laterally from the blast chamber) against the forward faces of the webs 3| by means of bolts 30 extending through these flanges and into the webs 3|. The front faces of the webs 3| are cut to the proper angle so that when the riser conduit I1 and housing |3 are secured in place with respect to the backhead ID the jets issuing from the blast chamber have the desired direction.

Steam is supplied to the high pressure chamber through a pipe line 32 entering through the side wall of the housing I3 and connecting to the blast chamber. Likewise the low pressure chamber 26 is supplied with steam from a low pressure line 33.

Referring now to the distributor plate, generally indicated at 24, and looking at Figures 2, 3 and 4, the distributor plate comprises a central table portion 34 which is fiat and slopes slightly downwardly and forwardly. Side portions 35' at either side of the table portion are grooved slightly toward their respective ends and diverge to cooperate with the end jets 21a of the high pressure blast and with the low pressure blasts to deliver coal to side portions of the firebox. The plate is located closely adjacent the bottom'wall of the firing opening and terminates at its forward end within the firing opening so that it is protected to some extent from the severe heat of the fire.

Integral with the distributor plate and located above the respective side grooves 35 are elevated chutes or channels, generally indicated at 36. The chutes are grooved as indicated by the arrow 31, which grooves gradually become deeper and wider toward their delivery ends. The grooves extend rearwardly to the low pressure jets 38 located at the ends of the blast chamber slightly below its ledge Hat. The chutes extend into the firebox and curve outwardly past the sides of the firing opening.

These chutes cooperate with the low pressure jets 38 to distribute coal over rear corners of the firebox. Because of their elevation and the extent to which they extend into the firebox they satisfactorily reach the rear corners. Whereas for the desired coal distribution it is desirable to screen the coal flowing over the central portion of the ledges 2| and 2|a. to distribute the larger particles with high pressure jets, such is not necessary for the coal flowing over the extreme side portion of the ledge 2|. The coal going over the sides is more homogeneous in size because the larger particles tend to move over the central portion of the ledge 2|. Therefore the low pressure jets 38 are satisfactory for handling the coal moving through the chutes 36.

The grooves of the chutes deepening and widening as,they do toward their delivery ends take care of the expanding steam jets 38 and serve to offset the possibility of coal catching in and plugging the grooves. The walls 39 of the chutes (forming the inner and forward walls thereof) are increased in thickness toward the delivery end to aid their withstanding the heat of the firebox.

These two arms or chutes 36 are integrally supported from the main portion 34 of the distributor plate by upright webs 40 which, as shown in dotted lines in Figure 2, start from the rearward face of the distributor plate, turn at an angle and diverge from each other, forming walls paralleling the channel portions 35. The walls thus formed prevent coal going over the outside of the channel portions 35 where it mightfall between the distributing mechanism and the sides of the firing opening and burn.

The distributing plate 24 is removably secured to and supported from the blast chamber as follows: Extending forwardly from the extreme side portions of the body portion of the blast chamber are two supporting arms 4| provided at their forward ends with lips 42 extending upwardly. Extending sidewardly from either side of the distributor plate and in the general plane of the chutes 36 are elongated lugs 43 extending downwardly below the rearward portions of the chutes 36 and extending laterally just beyond the outside edges of the supporting arms 4| on which lugs 43 are adapted to rest. The rearward faces of the lips 42 slope rearwardly and the forward faces of the lugs 43 slope in a similar direction so that as these lugs move into locking position in back of the lips the sloping faces, contacting, force the rearward vertical faces of the chutes 36 against corresponding forward vertical faces SI] of the blast chamber.

The distributor plate is aligned with the blast chamber as the two are assembled by shoulders 48 located on the blast chamber outside of fingers 21a. These'shoulders guide the inside surfaces 'ing it.

ofthe vertical webs 40 andso serve to centrally align the-distributor plate with the-blast cham-- ber; Also-the faces 56, turning outward as they do andspaced as they are, serve to center the" distributor plate and the blast chamber when the two are thus interengaged.

The distributorplate is prevented from tipping downwardly: about the arms 4| and its position with respect to the horizontal is determined by contact between a curved rearward face 4! of the distributor plate and a similarly curved forward face of the blast'chamber. These contacting faces both-slope rearwardly and serve to lock the distributor plate in engagement with the blast chamber-so that it can be unlocked only by tippingthe forward end of the distributing plate clockwise as shown in Figure i.

Referring to Figure 10, as the coal moves over the-blast chamber ledge Zia, the coal going over the central portion is screened by the fingers 2'!- and the larger particles move into the paths of the jets of the fingers and the smaller particles move into the path of the sheet jet as described. The coal is guided by the table portion of the distributor plate over the firebed. This much of the distributing apparatus may be made to coverthe areas A, B, C and D as shown in Figure 10. The coal moving over the extreme side portions of the ledge Zia falls into the grooves 31 of the elevated chutes and is carried by the jets 38' to the rear corner portions of the firebox, i. e. areas E and F.

The substantially greater elevation of the chutes 36, which elevation is desirable to enable the jets to reach the corner areas E and F, permits the central portions S l and 35 of the distributor plate, and indeed the whole blast chamber, to be placed lower in the firing opening than would otherwise be possible. This leaves more room in the firing opening for workmen to enter and overcomes the'necessity for enlarged firing openings. Further, by making the channels 36 elevated as they are, it is possible to put more coal into the rear corners. Referring to Figure 3, the amount of coal flowing into these corners may be controlled by means of adjustable slides 49 ex tending through the sides of the distributor hous- As these slides are pushed toward one another they reduce the amount of coal flowing into the channels 38, and as they are retracted from each other they increase the flow of coal to the channels.

Whereas the construction just described provides for an improved coal-distributing device which canbe located lower in the firing opening and which improves the distribution of the coal feed to the rearward corners of the firebox, the elevated chutes 36 extending as they do intothe firebox proper, and exposed as they are to the intense heat of the firebox are subject to more rapid deteriorationthan is the main body of the plate 24. Referring to Figures 5 through 10, a modification of the distributor plate mechanism isshown in which this difiiculty is overcome by making the chutes 35 removable from the body of the distributor plate so that the chutes may be replaced independently of the main body portion.

Referring to Figure 5, the central or table portion '3 1 of the distributing mechanism 24 is shaped the same as shown in Figure 2, but as indicated along the line a break is provided in the chutes 36 so. that they now comprise two portions generallyindicated at 1! and 12 (Figure 9). The portion .H; is integral with the body of the distributor plate' and carries the downwardlymrojecting elongated lug 43 which cooperatesasdescribed in connection with Figure 2 withthesupporting arms H extendingforwardly from the blast chamber to removably. support the disas to come just inside the supporting arms 4H- extending forwardly from the blastchamber so as not to interfere with these 'armsin their locking engagement with the lugs 53-. Y The upstanding lips M and the lugs 63- have engaging surfaces which both slope forwardly, as shown in Figure 7. The tongue 13 and groove l3wserve to keep the chute sections 12 in proper alignment and the inclined contacting surfaces between the lugs 43' and the lips 14 serve to keep the two sections intight abutting relationship along the'line '10.

The forward ends of the chute sections '82 are prevented from tipping downwardly about the lugs 43 by contact between the underf'ace 12a of the chute sections-T2 and the top surface 40a of the webs 45?. y

Each section 12 thus maintained in" locking engagement with respect to the" integral section's Ii may be removed. by raising its forward end upwardly to disengage the' lip M from the lug 33, and then sliding the section 12" clear of the base portion of the plate 24. A new removable chute section 12 may be hooked in place by reversing the operation. This construction thus provides for the replacing of the chutes 36 independently of the body portion of the distributing apparatus.

As various embodiments might be made of this invention, and as various changes might be made in the construction herein described, all without departing from the scope of the invention, it is to be understood thatall matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

. I claim:

1. In apparatus for distributing over a firebox through a firing opening in the back wall. thereof coal supplied thereto by conveying apparatus, in combination, a blast chamber adapted 'to' be located within said firing opening and. adjacent the bottom wall thereof and constructed to di rect over the firebox a plurality of steam jets to distribute over the firebox coal falling into the paths of said steam jets, said steam jets-being located in at least two different horizontal planes, and coal-guiding apparatus 1ocated.witl'i-- in said firing opening forwardly of said blast chamber, and cooperating with said jets to guide the coal particles moving under the influence of the "steam jets, said coal-guiding apparatus comprising a table portion having coal supporting and guiding surfaces for cooperating with the lower jets to distribute the coal over the central, front and side portions of said firebox, and two elongated chute portions having coal-supporting and guiding surfaces elevated above either side of said table portion and curved toward the re.- spective rearward comers of said firebox to cooperate with the upper steam jets to distribute 'coal'-over'- th'e rear-Ward corners of said firebox,

said chute portions being removably supported by said table portion.

2. In apparatus for distributing over a firebox through a firing opening in the back wall thereof coal supplied thereto by conveying apparatus, in combination, a blast chamber adapted to be located within said firing opening and adjacent the bottom wall thereof and constructed to direct over the firebox a plurality of steam jets to distribute over the firebox coal falling into the paths of said steam jets, said steam jets being located in at least two different horizontal planes, and coal-guiding apparatus located within said firing opening forwardly of said blast chamber, and cooperating with said jets to guide the coal particles moving under the influence of the steam jets, said coal-guiding apparatus comprising a table portion having coal guiding and supporting surfaces for cooperating with the lower jets to distribute the coal over the central, front and side portions of said firebox, two elongated chute portions having coal guiding and supporting surfaces elevated above either side of said table portion and curved toward the respective rearward corners of said firebox to cooperate with the upper of said steam jets to distribute coal over the rearward corners of said firebox, and vertical diverging webs extending between said table portion and said chute portions to limit the sideward movement of the coal particles passing over said table portion.

3. In apparatus for distributing over a firebox through a firing opening in the back wall thereof coal supplied thereto by conveying apparatus, in combination, a blast chamber adapted to be located within said firing opening and adjacent the bottom wall thereof and constructed to direct over the firebox a plurality of steam jets to distribute over the firebox coal falling into the paths of said steam jets, said steam jets being located in at least two different horizontal planes, and coal-guiding apparatus located within said firing opening forwardly of saidblast chamber, and cooperating with said jets to guide the coal particles moving under the influence of the steam jets, said coal-guiding apparatus comprising a table portion having coa1 guiding and supporting surfaces for cooperating with the lower jetsto distribute the coal over the central, front and side portions of said firebox, two elongated chute portions having coal guiding and supporting surfaces elevated above either side of said table portion and curved toward the respective rearward corners of said firebox to cooperate with the upper steam jets to distribute coal over therearward corners of said firebox, and adjustable means rearward of said blast chamber for controlling the flow of coal to said chute portions.

4. Coal distributing apparatus utilizing a steam blast for blowing coal over a firebed, consisting in the combination of a distributor plate having a substantially horizontal coal guiding and supporting surface over which coal flows under the influence of said steam blast, channels on either side of said surface through which coal passes under the influence of said blast to the side portions of the firebed, and elevated chutes having coal guiding and supporting surfaces located directly above and spaced from said first-mentioned channels for directing coal flowing under the influence of said steam blast to the rearward corners of said firebox. V

5. Coal distributing apparatus utilizing a steam blast for blowing the coal over a firebed, consisting ,inthe combination of a distributor plate having a substantially horizontal coal guid-- ing and supporting surface over which coal flows under the influence of said steam blast, channels on either side of said surface through which coal passes under the influence of said blast to the side portions of the firebed, elevated chutes having coal guiding and supporting surfaces located directly above and spaced from said first-mentioned channels for directing coal flowing under the influence of said steam blast to the rearward corners of said firebox, and approximately vertical webs extending up from the far sides of said channels to said chutes to support said chutes and limit the sideward travel of the coal.

6. Coal distributing apparatus adapted to be mounted in the lowermost portion of the handfiring opening ofa locomotive boiler backhead so as to form a minimum obstruction to said flring opening, said distributing apparatus comprising, in combination, a blast chamber adapted to emit blasts over said firebox in several different horizontal planes, one above the other, a coal distributing device having a central portion provided with a substantially horizontal coal guiding and supporting surface and adapted to cooperate in the distribution of coal with the lower of said steam blasts, diverging depressed channels on either sideof said central portion for guiding the coal under the influence of said steam blast to the sides of said firebox, and elongated chutes located above and crossing said channels and having coal guiding and supporting surfaces for guiding the coal under the influence of the upper of said steam blasts, said chutes extending appreciably forward of said channels and central portion and being curved outwardly at their delivery ends.

7. Coal distributing apparatus adapted to be mounted in the lowermost area of the hand-firing opening of a locomotive so as to form a minimum obstruction to said firing opening, said distributing apparatus comprising, in combination, a coal guiding member having a central portion provided with a substantially horizontal coal guiding and supporting surface, and with diverging, depressed channels on either side of said central portion, and elongated coal supporting and guiding chutes located above and crossing said channels, said chutes extending appreciably forward of said channels and central portion and being curved outwardly at their delivery ends.

8. In coal distributing apparatus, in combination, a blast chamber adapted to emit a steam blast for blowing coal over a firebed, a distributor plate having a substantially horizontal coal guiding and supporting surface over which coal flows under the influence of said steam blast, channels on either side of said surface through which coal passes under the influence of said blast to the side portions of the firebed, elevated chutes having coal guiding and supporting surfaces located directly above and spaced from said first-mentioned channels for directing coal flowing under the influence of said steam blast to the rearward corners of said firebox, and means rearward of said blast chamber for regulating the presentation of coal selectively to said elevated chutes.

9. The combination with a firebox provided with a back wall having a firing opening, of coal distributing mechanism disposed in said opening, said mechanism including lower coal distributing means having a plurality of relatively extensive coal guiding and supporting surfaces constructed to handle the major portion of the coal supplied to the firebox, and to guide it to the central and side portion and far corners of the firebox, said surfaces terminating within the confines of said opening and thereby being protected from the heat of the fire in said firebox by the walls of said firing opening, and upper coal distributing means having coal guiding and supporting surfaces elevated substantially above the lower means and extending into said firebox beyond said firing opening and thereby being exposed to the destructive heat of the fire in said for emitting two series of fluid-pressure jets, one series in a horizontal plane adjacent the bottom of said firing opening and the other series in another horizontal plane above the said bottom, a main distributor plate adapted to be centrally located in said firing opening adjacent the bottom thereof so that the lowermost of the series of jets will propel coal over the upper surface thereof, said upper surface having such formation as to direct said coal to the central, front and side portions only of the firebox, a pair of side-delivery chutes adapted to be mounted in the firing opening at the sides thereof above said main distributor plate, in such position that the upper series of jets will propel coal therealong, the delivery ends of said chutes being elevated substantially above the main distributor plate and curved to direct coal flowing therethrough to the rear corners of said firebox, and means for delivering coal to the rear ends of said plate and said chutes,

WILLIAM THOMPSON HANNA. 

